Modulation of P-glycoprotein-mediated resistance by kaempferol derivatives isolated from Zingiber zerumbet

This study examined the effects of the kaempferol derivatives extracted from Zingiber zerumbet on the accumulation and efflux of [(3)H]-daunomycin (DNM) in P-glycoprotein (P-gp) overexpressing multidrug resistant (MDR) human breast cancer cells, MCF-7/ADR. Of six kaempferol derivatives extracted from Z. zerumbet, kaempferol-3-O-methyl ether (1) and kaempferol-3,4'-O-dimethyl ether (2) showed a potent P-gp inhibitory effect as great as verapamil, a well-known P-gp inhibitor. The P-gp inhibitory activity of these two compounds was through a 3-fold increase of the level of [(3)H]-DNM accumulation and a decrease of P-gp-mediated efflux. These results suggest that the kaempferol derivative components of Z. zerumbet can be used as a scaffold for developing agents that reverse P-gp-mediated MDR in human cancer chemotherapy.     

Impact of epidermal growth factor receptor (EGFR) kinase mutations, EGFR gene amplifications, and KRAS mutations on survival of pancreatic adenocarcinoma

BACKGROUND: Erlotinib, in combination with gemcitabine, has shown clinical benefits in pancreatic adenocarcinoma patients. The presence of EGFR mutations and increased EGFR copy numbers in pancreatic adenocarcinoma was explored. METHODS: Sixty-six pancreatic cancer patients were included in the analysis. The EGFR mutation was analyzed by DNA sequencing of exons 18-21 in the tyrosine kinase domain. KRAS mutation was analyzed by sequencing codons 12, 13, and 61. Quantitative real-time polymerase chain reaction was performed to analyze the copy number of EGFR. RESULTS: In the current study the EGFR mutation was harbored in only 1 (1.5%) of the 66 inoperable or metastatic pancreatic adenocarcinoma patients. Amino acid substitution was detected in exon 20 of the EGFR gene. Increased EGFR copy numbers (> or =3.0 per cell) were detected in 26 (41%) patients. There was only 1 patient, who had a highly increased EGFR copy number (> or =6.0 per cell), who died, 2.1 months from the date of diagnosis. The EGFR amplification did not significantly influence survival in pancreatic adenocarcinoma patients (P = .935). Thirty-two (49%) of the 65 pancreatic adenocarcinomas examined harbored a point mutation in codons 12 (n = 31) and 61 (n = 1) of the KRAS gene. The presence of a point mutation in codon 12 adversely influenced survival of pancreatic cancer patients (P = .030). CONCLUSIONS: The incidence of somatic mutations in the tyrosine kinase domains of EGFR was very low and the increased gene copy number of EGFR did not significantly influence survival.     

Assessment of Hepatic Arterial Anatomy in Keeping with Preservation of the Vasculature While Performing Pancreatoduodenectomy: An Opinion

Background Pancreatic surgeons often must make decisions regarding hepatic artery (HA) resection while performing a pancreatoduodenectomy (PD). The purpose of this report was to review and summarize HA resection experience with a focus on vascular preservation during PD and to develop a useful guideline for pancreatic surgeons in dealing with these needs. Methods We reviewed 1324 cases that had available computed tomographic and angiographic findings and summarized the problematic HA variations encountered in PD. In reviewing our PD series (n = 254), we have created a set of guidelines that enable a pragmatic approach to the unique variations in HA and the risks of cancer invasion. Results Challenging HA variations during PD were found in 20.1% of the cases and included the common HA arising from the superior mesenteric artery (SMA) (2.34%), a replaced right HA (RHA) from the SMA (9.82%), an RHA or left HA from the gastroduodenal artery (0.97%), and the right anterior or right posterior HA from the SMA (1.06%), among others. In our PD series, the problematic HAs (15.8%) were preserved, except for a single case (0.4%) in which PD involved en bloc resection of the RHA from the SMA due to a cancerous invasion and without right hemihepatectomy. Conclusions Surgeons should have knowledge of the anatomically variable vasculature of the HA when planning for PD. Preoperative imaging studies can aid and should be performed in anticipation of the potential HA variations during PD.     

Contemporary results of open repair of ruptured descending thoracic and thoracoabdominal aortic aneurysms

OBJECTIVE: The purpose of this study was to evaluate the results of open repair for ruptured descending thoracic and thoracoabdominal aortic aneurysm (RDTAA). METHODS: A retrospective review identified 41 consecutive cases of open surgical repair in 40 patients presenting with nontraumatic, atherosclerotic RDTAA from 1996 to 2006. Patients with traumatic injuries or complicated dissections were excluded. Patient characteristics and preoperative, intraoperative, and postoperative variables were collected from the medical record. Univariate and logistic regression were used to identify factors contributing to mortality and morbidity in these patients. RESULTS: The operative mortality rate was 26.8% (11/41). All but two deaths occurred within 24 hours of operation; seven were intraoperative. Overall actuarial survival rates at 1 and 2 years were 53.7% and 47.1%, respectively. For those who survived to hospital discharge, the respective numbers were 73.3% and 64.4%. Intraoperative hypotension and blood transfusion requirements were independent predictors of perioperative death. Octogenarians had a mortality rate equivalent to that of the younger population (25% vs 27.6%; not significant). There was a strong trend toward an improved outcome in the latter part (2003-2006) compared with the first part (1995-2002; 13.6% vs 42.1%, respectively; P = .075). CONCLUSIONS: Direct open repair for RDTAA can be achieved with acceptable mortality and morbidity rates even in elderly patients. Improved outcome can be expected with increased volume and experience. This series should help establish a reference against which the results of endovascular endeavors and hybrid procedures could be compared.     

Low risk prostate cancer in men under age 65: the case for definitive treatment

The management of low risk prostate cancer, defined as Gleason’s sum ≤6, PSA <10 ng/ml, and clinical stage T1c to T2a, remains controversial. There is substantiating evidence to suggest that a subset of early stage, low risk cancers can cause significant patient morbidity and death in the long term. Studies have shown that the natural history of untreated prostate cancer is to progress, particularly after 15 years of followup. The majority of men seeking definitive surgical treatment in contemporary series fall within 55 to 65 years of age and are expected to enjoy an overall life expectancy ranging from about 15 to 30 years, placing these men at long-term risk for disease progression and prostate cancer-specific death if managed expectantly. During the past 2 decades, refinements in surgical technique and in the delivery of external beam radiation have resulted in excellent long-term cancer control and favorable quality of life outcomes following treatment. Active surveillance with selective delayed intervention assumes that an individual’s cancer will not progress outside the window of curability during the surveillance period, that markers for disease progression are reliable, and that patients are compliant. Until we understand better the long-term natural history of untreated prostate cancer, have more reliable and accurate markers to detect disease progression with certainty, and can risk stratify more precisely the subgroup of men with low risk cancers who will eventually succumb to their disease, early definitive therapy seems prudent.